appgroup_mem_sz - Maximum size of application group memory set configuration parameter
This parameter has been deprecated since Version 9.5,
but is still being used by pre-Version 9.5 data servers and clients. Any value specified for this
configuration parameter will be ignored by the database manager in Db2® Version 9.5 or later
releases.
In Version 9.5, it has been replaced by the appl_memory
configuration parameter.
Note: The following information applies only to pre-Version 9.5 data servers and
clients.
This parameter determines the size of the application group shared memory segment.- Configuration type
- Database
- Parameter type
- Configurable
- Default [range]
-
- UNIX Database server with local clients
- 20 000 [1 - 1 000 000 ]
- Windows Database server with local clients
- 10 000 [1 - 1 000 000 ]
- Database server with local and remote clients
- 30 000 [1 - 1 000 000 ]
- Partitioned database server with local and remote clients
- 40 000 [1 - 1 000 000 ]
- Unit of measure
- Pages (4 KB)
Information that needs to be shared between agents working on the same application is stored in the application group shared memory segment.
In a partitioned database, or in a non-partitioned database with intrapartition parallelism enabled or concentrator enabled, multiple applications share one application group. One application group shared memory segment is allocated for the application group. Within the application group shared memory segment, each application will have its own application control heap, and all applications will share one application group shared heap.
The number of applications in one application group is calculated by:
appgroup_mem_sz / app_ctl_heap_szThe application group shared heap
size is calculated by:
appgroup_mem_sz * groupheap_ratio / 100The size
of each application control heap is calculated by:
app_ctl_heap_sz * (100 - groupheap_ratio) / 100Recommendation: Retain the default value of this parameter unless you are experiencing performance problems.